Fix typos in clang

Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:

  archtype
  cas
  classs
  checkk
  compres
  definit
  frome
  iff
  inteval
  ith
  lod
  methode
  nd
  optin
  ot
  pres
  statics
  te
  thru

Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)

Differential revision: https://reviews.llvm.org/D44188

llvm-svn: 329399
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index a85a22a..79ac53c 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4463,7 +4463,7 @@
   CollectInheritedProtocols(IDecl, InheritedProtocols);
   if (InheritedProtocols.empty())
     return false;
-  // Check that if every protocol in list of id<plist> conforms to a protcol
+  // Check that if every protocol in list of id<plist> conforms to a protocol
   // of IDecl's, then bridge casting is ok.
   bool Conforms = false;
   for (auto *Proto : OPT->quals()) {
@@ -6545,7 +6545,7 @@
       S += "{objc_class=}";
       return;
     }
-    // TODO: Double check to make sure this intentially falls through.
+    // TODO: Double check to make sure this intentionally falls through.
     LLVM_FALLTHROUGH;
   }
   
@@ -6584,7 +6584,7 @@
     if (OPT->isObjCClassType() || OPT->isObjCQualifiedClassType()) {
       // FIXME: Consider if we need to output qualifiers for 'Class<p>'.
       // Since this is a binary compatibility issue, need to consult with runtime
-      // folks. Fortunately, this is a *very* obsure construct.
+      // folks. Fortunately, this is a *very* obscure construct.
       S += '#';
       return;
     }